Your CPU is more then likely holding you back yes. It's clock speed firstly and the fact that its a dual core processor as well are what keeping you back from higher frames with your current card yes. Stepping up to a i5 3570k would yield significant frame increase as well as perhaps the cheaper i5 3470. You have a mid level card which is almost a high end card you will need more cpu power to bolster your card as well as a suggested 8 gigabytes of ram.